USB interface chip CP2102 data introduction (I)

At present, most of the instruments and equipment use RS232 interface to communicate with the computer. However, with the development of computer technology, the USB standard interface supporting hot plugging will replace the RS232 interface, so the computer will be less and less configured or even not equipped with RS232 interface. Although the RS232 interface and the USB interface are serial connections, their data formats, communication protocols, signal levels, and mechanical connections are different. In this way, the computer cannot control the existing equipment, and to solve this problem, the RS232 interface of the existing equipment must be converted into a USB interface. There are two ways to implement this conversion. One solution is to fully develop the system from the underlying firmware of the hardware. This solution is rarely used because of its high development cost and difficulty, and the limitations of the microcontroller. The other solution is USB/ RS232 bridge devices such as CP2102 and CP2103 are designed. The computer virtualizes an RS232 interface through the USB interface and connects with traditional device devices. The device-to-computer interface is in the form of a USB interface.

Introduction to CP2102/CP2103:

SILICon Laboratories' USB interface and RS232 interface converter CP2102/CP2103 is a highly integrated USB-UART bridge that provides an easy solution for implementing RS232 conversion USB with minimal component and PCB space. As shown in Figure 1, the CP2102/CP2103 includes a USB function controller, USB transceiver, oscillator, and asynchronous serial data bus (UART) with all modem control signals, using a 5 mm × 5 mm MLP-28 Package.

As a USB/RS232 bidirectional converter, CP2102/CP2103 can receive USB data from Fengfeng and convert it into RS232 stream format and send it to peripherals. On the other hand, it can convert data from RS232 peripheral to USB data format. To the host, which includes control and handshake signals.

Asynchronous serial data bus (UART) interface:

The CP2102/CP2103 UART interface includes TX (transmit) and RX (receive) data signals as well as RTS, CTS, DSR, DTR, DCD, and RI control signals. The UART supports RTS/CTS, DSR/DTR and X-On/X-Off handshaking.

The UART is programmed to support various data formats and baud rates. Program the UART data format and baud rate on the COM port of the PC.

Internal EEPROM:

The CP2102/CP2103 integrates an internal EEPROM to store information such as the USB vendor ID, product ID, product description, power supply parameters, device version number, and device serial number as defined by the device manufacturer. Note that a dedicated serial number is required for OEM applications that may use multiple CP2102/CP2103 based connections to the same PC.